Claude Fable 5.1 vs Claude Haiku 4.5
Claude Fable 5.1 leads the LLM Stats Score 55.7 to 25.7. Claude Haiku 4.5 is 10.0x cheaper per token.
Anthropic · Anthropic · Updated for 2026
Which is better?
Claude Fable 5.1 leads the overall LLM Stats Score 55.7 to 25.7, ranking #2 overall.
On price, Claude Haiku 4.5 is roughly 10.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Claude Fable 5.1 also accepts a larger context window (1,000,000 input tokens), making it the stronger choice for long documents and large codebases.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Claude Fable 5.1
- overall performance matters — it scores 55.7 and ranks #2 on LLM Stats
- your work emphasizes reasoning and coding — it leads those capability indexes
- you process long inputs — it offers a 1,000,000 token context window
- you want the most recent training data — it shipped Sep 2026
Choose Claude Haiku 4.5
- cost matters — it's about 10.0x cheaper per token
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
7 reported for Claude Fable 5.1 · 12 for Claude Haiku 4.5
Claude Fable 5.1 and Claude Haiku 4.5don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Fable 5.1 ($10.00/1M tokens) is 10.0x more expensive than Claude Haiku 4.5 ($1.00/1M tokens).
For output processing, Claude Fable 5.1 ($50.00/1M tokens) is 10.0x more expensive than Claude Haiku 4.5 ($5.00/1M tokens).
In conclusion, Claude Fable 5.1 is more expensive than Claude Haiku 4.5.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Claude Fable 5.1 accepts 1,000,000 input tokens compared to Claude Haiku 4.5's 200,000 tokens. Claude Fable 5.1 can generate longer responses up to 128,000 tokens, while Claude Haiku 4.5 is limited to 64,000 tokens.
Input capabilities
Documented input modalities across available providers
Both Claude Fable 5.1 and Claude Haiku 4.5 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude Fable 5.1
Claude Haiku 4.5
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
Claude Fable 5.1 was released on 2026-09-01, while Claude Haiku 4.5 was released on 2025-10-15.
Claude Fable 5.1 is 11 months newer than Claude Haiku 4.5.
Sep 1, 2026
2 weeks ago
10mo newerOct 15, 2025
11 months ago
Knowledge Cutoff
When training data ends
Claude Haiku 4.5 has a documented knowledge cutoff of 2025-02-01, while Claude Fable 5.1's cutoff date is not specified.
We can confirm Claude Haiku 4.5's training data extends to 2025-02-01, but cannot make a direct comparison without Claude Fable 5.1's cutoff date.
—
Feb 2025
Provider Availability
Claude Fable 5.1 is available from Anthropic. Claude Haiku 4.5 is available from Anthropic, DeepInfra, Vertex AI.
Claude Fable 5.1
Claude Haiku 4.5
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude Fable 5.1 and Claude Haiku 4.5 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude Fable 5.1 vs Claude Haiku 4.5.